1. Technical Field
The present invention relates to an electronic apparatus in which a cap member is bonded to a substrate with an electronic component bonded so as to seal the electronic component, a method of manufacturing a substrate, and a method of manufacturing an electronic apparatus.
2. Related Art
In the related art, a surface mounting electronic apparatus is widely used in which an electronic component bonded to a substrate is sealed by a cap member. This electronic apparatus is used as a clock source in an electronic circuit for various electronic apparatuses, for example, OA equipment and consumer equipment, such as an information communication instrument or a computer. As an example of such an electronic apparatus, a piezoelectric device is widely used in which a piezoelectric vibrating piece serving as an electronic component is bonded to a substrate and a concave cap member is bonded to the substrate so as to cover the piezoelectric vibrating piece, such that the piezoelectric vibrating piece is sealed airtight in a concave space defined by the substrate and the cap member (for example, see JP-A-2003-318690).
The piezoelectric device (quartz vibrator) described in JP-A-2003-318690 has a flat plate-shaped substrate (flat plate-shaped substrate), a piezoelectric vibrating piece (quartz piece), and a concave cap member (metal cover) having a flange. The substrate made of ceramic is provided with external mounting terminals on one main surface as an outer bottom surface of the piezoelectric device and a metal layer (metal film) in an edge portion of the other main surface. Inside the metal layer is provided with a bonding terminal (quartz terminal) to which the piezoelectric vibrating piece is bonded. One end portion of the piezoelectric vibrating piece is bonded to the bonding terminal of the substrate by a bonding member, such as a conductive adhesive, and positioned inward of the opening section of the cap member and the peripheral end of the substrate. A soldering material comes into contact with around the contact portion between the peripheral surface of the cap member and the metal layer of the substrate, and the soldering material is heated until molten for soldering. Thus, the piezoelectric vibrating piece is sealed airtight in the concave space defined by the substrate and the cap member.
However, in the piezoelectric device described in JP-A-2003-318690, the contact portion for bonding the cap member and the substrate is limited to only the opening section of the cap member. For this reason, bonding strength between the cap member and the substrate may be degraded, impact resistance or bonding strength may be deteriorated, or sealing airtightness may be degraded due to deterioration in impact resistance or bonding strength.
The cap member may be misaligned on the substrate to which the piezoelectric vibrating piece is bonded and, for example, the cap member may protrude from the periphery of the piezoelectric device, such that the dimension standard of the planar contour may not be satisfied, or bonding strength or airtightness of the cap member may be deteriorated.